Our wonderful Clocktower Manager, Bill, asked for this one!
"Knock Three Times" is a popular song written by L. Russell Brown and Irwin Levine, and recorded by Tony Orlando and Dawn in 1970. The song was released as a single in November 1970. The single hit number one on the Billboard Hot 100 in January 1971 and eventually sold six million copies, also claiming the number-one spot on the UK Singles Chart.
A video for this song: